Conventionally, refrigeration systems have been known where the high pressure in the refrigeration cycle is controlled in such a way as to become a target high pressure value. For example, in the system of JP-A No. 2011-47552, control of the high pressure of the refrigerant is performed in consideration of a drop in pressure resulting from the liquid head of a connection pipe caused by a difference in the installation positions of a heat source unit and utilization units. Specifically, the longest length in the scope of warranty set in the system is not manually input as the height of the connection pipe, but rather a connection pipe height determination processing operation for computing the height is performed after the installation of the system, whereby the height is calculated. Controlling the operating frequency of a compressor in accordance with the height, for example, on the basis of this height is disclosed in JP-A No. 2011-47552, Because of this, a situation where the high pressure ends up becoming higher than necessary is avoided, and the system can operate efficiently.